The development of a rigorous sampling methodology for a long-term annual index of recruitment for finfish species from southwestern WA
Department of Primary Industries and Regional Development (DPIRD) WA
Suzanne G. Ayvazian
There is a critical need for a reliable stock monitoring system for future management of the important multispecies commercial and recreational finfish fishery in the south west of Western Australia. Specifically a robust annual recruitment index for monitoring long term trends in abundance for the key finfish species is needed. The proposed recruitment index survey system is also required to complement and improve the usefulness of existing long-run commercial catch and effort records. In order to develop a cost effective index system, there is a need to collect sufficient data on the spatial and temporal abundance of each species, within a rigorously planned experimental framework, to allow maximum use of current statistical techniques. The comprehensive statistical approach to the survey design proposed for this project, although not previously applied to the development of finfish recruitment indices, will enable the dimensions, and hence cost, of the long term field sampling to be minimised.
1. Develop a robust, low cost, effective sampling method for an on-going recruitment index for seven key inshore fin fish species from southwestern Australia.
2. Determine the size and age structure of the commercial catch of these seven species.
3. Determine the effect of spatial and temporal factors (eg. geographic location, season, day time, lunar cycle, tidal cycle, temperature, salinity and wind) on the abundance of each species.
4. Determine the local depletion and recovery rate after intensive sampling for each species.
Principal Investigator: D. Gaughan, S. Ayvazian, G. Nowara and M. Craine